U.S. Pat. No. 4,082,550 describes heterogeneous photoconductive compositions comprised of particles of an organic photoconductor that is chemically sensitized with a monomeric hexachlorocyclopentene and dispersed in a cellulose nitrate binder.
European Patent Application No. 0/069 397 describes an electrophotographic plate having a charge generating layer and a charge transporting layer on an electrically conductive substrate. The charge transporting layer incorporates a dicyano vinyl compound in combination with an electron donating compound.
In photoconductor elements of the type employing a charge generating layer and a charge transporting layer, it has been common to employ in the charge transporting layer either a polymer, such as polyvinyl carbazole, or a composition comprised of an electron-donating, charge transporting, low molecular weight organic compound dissolved in an insulating binder polymer. These charge transporting layers commonly suffer from one or more problems, such as high dark decay, insufficient electron charge transport activity, fluctuations in surface potential upon repeated use, decreasing sensitivity with repeated use, and a gradually increasing residual potential upon repeated use. Consequently, new electron-transport agents that exhibit sufficient sensitivity, but do not exhibit disadvantages such as above indicated would be desirable for us in positively charged photoconductor elements.
So far as now known, no one has heretofore proposed the use of tetrasubstituted, dicyano vinyl substituted cyclopentadienes as electron-transport agents.